Meet 17-month-old Wren, whose mum froze her eggs three years before her birth

Pop star Rita Ora put fertility pretty firmly in the minds of young women recently when she spoke publicly about her decision to freeze her eggs in her 20s to future-proof her chance of having kids.

With more women opting to wait to start families, Seven Sharp got thinking - how viable are the 'back up' options?

One baby, 17-month-old Wren Kingston, is the picture of perfection.

"They call them frozen egg babies, born through Fertility Associates in New Zealand. so yeah, she's pretty unique," Wren's mum Tara Kingston said.

Ms Kingston always knew she wanted to be a mum, but at nearly 36 and life hadn't taken her in that direction, she decided to assess her options.

"I was just becoming increasingly aware of timeframes and biological clocks and all that sort of stuff, so it was more around if it was going to happen, and I knew it would, then when, and how do I actually, in a terrible way, buy myself a bit of time?" she said.

Ms Kingston eventually decided to harvest and freeze her eggs, where they stayed for three years, before she decided the time was right to use them through IVF.

"I loved the fact that it didn't matter what happened in my life. If I wanted to wait two years or five years, I could do, and I could actually make sure that I was 100 per cent ready, and my world was ready for Wren so it is, it's actually lovely to be able to have that control."

With egg 'snap freezing' technology developing rapidly in the country, Fertility Associates is seeing more and more women investigating what's known as 'social egg freezing'.

Fertility Associates' Dr Andrew Murray said, "We would get, perhaps, 50 per cent of the eggs to survive the freeze/thaw process 10 years ago. Now, it's over 90 per cent that are surviving that process. but more importantly, the number of women who are now coming back to use those eggs and try and achieve pregnancies is increasing as well."

While the bulk of women opting to freeze their eggs are between 36 and 38 years of age, experts warn success can often come down to a woman's age.

"It's a bit of a conundrum because the most ideal time to freeze your eggs is usually when women aren't even thinking about having kids," Dr Murray said.

"Ideally, probably in your late 20s. For example, freezing eggs at 40, we can do it, but it's not going to be as likely to result in a baby as, say, freezing the eggs of a 30-year-old."

However, Dr Murray says there are no guarantees in fertility treatment.

"Egg freezing is not a guaranteed baby, but it's certainly a way of locking in time your potential fertility as a younger woman.

"It's about having choices, and having those at the earliest possible stage is a good idea."